1. Field of the Invention
The present invention relates to an image forming system.
2. Description of Related Art
In general, an electrophotographic image forming apparatus (such as a printer, a copy machine, and a fax machine) is configured to irradiate (expose) a charged photoconductor with (to) laser light based on image data to form an electrostatic latent image on the surface of the photoconductor. The electrostatic latent image is then visualized by supplying toner from a developing device to the photoconductor (image carrier) on which the electrostatic latent image is formed, whereby a toner image is formed. Further, the toner image is directly or indirectly transferred to a sheet, followed by heating and pressurization, whereby an image is formed on the sheet.
Conventionally, an image forming system has been known in which a sheet feeding apparatus that feeds a sheet to the above-mentioned image forming apparatus and a sheet ejection apparatus that ejects a sheet conveyed from the image forming apparatus are connected with the image forming apparatus at a preceding side and a succeeding side of the image forming apparatus, respectively.
Japanese Patent Application Laid-Open No. 8-91658 discloses a roll sheet feeding apparatus in which, when a paper jam is caused, roll-paper debris can be easily removed regardless of the leading end portion of the sheet. In accordance with the leading end portion of the sheet at the time when a paper jam is caused, the roll sheet feeding apparatus disclosed in Japanese Patent Application Laid-Open No. 8-91658 winds back the recording sheet to the upstream side when it is desirable to remove the recording sheet on the upstream side rather than the downstream side, whereas the roll sheet feeding apparatus cuts off the recording sheet when it is desirable to remove the recording sheet on the downstream side rather than the upstream side.
In the above-mentioned image forming system, a long sheet may cause a sheet jam in a sheet conveyance path of the long sheets when it is conveyed during an image formation operation for forming an image on the long sheet. In such a case, for recovery, the image formation operation is temporarily stopped, and then whether the long sheet in a stopped state causing the sheet jam has been removed by the user is determined before the image formation operation is restarted. However, removal of the long sheet which has been stopped during the conveyance is a very complicated task since the long sheet may possibly exist across two or more of the sheet feeding apparatus, the image forming apparatus and the sheet ejection apparatus. As such, a large burden has been disadvantageously imposed on the user to restart the image formation operation when a sheet jam is caused during an image formation operation on a long sheet.
It is to be noted that the technology disclosed in Japanese Patent Application Laid-Open No. 8-91658 is not designed for restarting an image formation operation without imposing a large burden on the user when a sheet jam is caused during the image formation operation on a long sheet, and therefore the technology disclosed in Japanese Patent Application Laid-Open No. 8-91658 does not include a configuration for such a purpose.